154
FXUS65 KTFX 231943
AFDTFX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREAT FALLS MT
143 PM MDT FRI OCT 23 2026
KEY MESSAGES
- WET SNOW AND WIND IMPACTS THROUGH EARLY THIS EVENING WILL
DIMINISH OVERNIGHT.
- GREATEST POTENTIAL FOR MODERATE SNOWFALL RATES AND WINDY CONDITIONS
THROUGH EARLY THIS EVENING ACROSS AREAS NEAR THE CENTRAL
MONTANA MOUNTAINS
- STRONG WINDS ACROSS PORTIONS OF NORTH-CENTRAL MT DIMINISH
FROM WEST TO EAST TONIGHT.
- DRIER BUT CONTINUED COOLER THAN AVERAGE CONDITIONS ARE
EXPECTED FOR THE WEEKEND INTO EARLY NEXT WEEK.
DISCUSSION
- METEOROLOGICAL OVERVIEW:
A FAIRLY VIGOROUS MID LEVEL WAVE ACCOMPANIED BY ANOMALOUS MOISTURE
CONTINUES TO LIFT NORTH ACROSS CENTRAL MT THIS AFTERNOON AHEAD OF
AN UPPER LEVEL TROUGH TRACKING EAST ACROSS THE ROCKIES. THIS WILL
CONTINUE TO SUPPORT WIDESPREAD PRECIPITATION ACROSS MUCH OF THE
AREA INTO EARLY THIS EVENING BEFORE DRYING BEHIND THE EASTWARD
MOVING TROUGH BRINGS AN END TO PRECIPITATION FROM WEST TO EAST
LATE THIS EVENING/OVERNIGHT.
POTENTIAL FOR EMBEDDED ISOLATED THUNDERSTORMS AND BRIEF MODERATE-
HEAVY PRECIPITATION RATES WILL DECREASE LATE THIS AFTERNOON AS THE
STRONGEST LIFT MOVES OUT OF THE AREA AND STABILITY INCREASES. THE
RISK FOR IMPACTS FROM LOCALIZED INTENSE PRECIPITATION HAS ALSO
DECREASED AS SNOW LEVELS CONTINUE TO LOWER, LEADING TO REDUCED
RUNOFF.
SURGE OF COLDER AIR FROM CANADA WILL CONTINUE TO SPREAD EAST ACROSS
REMAINING EASTERN PORTIONS OF NORTH-CENTRAL MT AND SOUTH THROUGH THE
VALLEYS OF SW MT THROUGH THE REST OF THIS AFTERNOON AND EVENING,
BRINGING A TRANSITION TO WET SNOW TO EVEN THE LOWEST ELEVATIONS
BEFORE PRECIPITATION ENDS LATER THIS EVENING. STRONGEST NORTH/NORTHWEST
WINDS WITH THE INITIAL SURGE OF THE COOLER AIRMASS ACROSS WESTERN
PORTIONS OF NORT-CENTRAL MT WILL BEGIN TO GRADUALLY DECREASE LATE
THIS AFTERNOON, WHILE EASTERN PORTIONS OF NORTH-CENTRAL MT WILL
HAVE WINDS PEAK LATE THIS AFTERNOON BUT NOT LIKELY TO NOTICEABLY
DIMINISH UNTIL LATER TONIGHT.
MODERATE TO HEAVY SNOWFALL RATES ARE MOST LIKELY TO OCCUR LATE THIS
AFTERNOON WITH LINGERING ANOMALOUS MOISTURE STILL IN PLACE
AHEAD OF THE UPPER TROUGH AXIS, WITH A TRANSITION TO MORE
OROGRAPHIC/UP-SLOPE FORCED SNOWFALL OCCURRING THIS EVENING BEFORE
PRECIPITATION ENDS. HIGH RESOLUTION MODEL ENSEMBLES HAVE THE
HIGHEST PROBABILITIES(80% OR BETTER) FOR 1"/HR RATED ACROSS THE
LITTLE BELT AND N-CENTRAL MT ISLAND RANGES AND NEARBY FOOTHILLS
BETWEEN 4PM AND 7PM WITH A 20-40% PROBABILITY FOR ADJACENT
PORTIONS OF FERGUS AND JUDITH BASIN COUNTIES INCLUDING THE JUDITH
GAP AND LEWISTOWN AREAS.
A DRIER WESTERLY FLOW MOVES ACROSS THE NORTHERN ROCKIES SATURDAY
BEHIND THE DEPARTING SYSTEM WITH A BROAD AREA OF UPPER LEVEL
TROUGHING LINGERING ACROSS WESTERN CANADA AND EXTENDING TO
OFFSHORE OF THE US WEST COAST. THIS HOLDS A COOLER THAN AVERAGE
AIRMASS ACROSS THE REGION INTO EARLY NEXT WEEK WITH SURFACE HIGH
PRESSURE CENTERED OVER THE CANADIAN PRAIRIES AND GENERALLY DRY
CONDITIONS PREVAILING THROUGH MONDAY. MEDIUM RANGE MODELS ARE
CONVERGING ON THE IDEA OF A LOBE OF ENERGY MOVING OUT OF THE
LARGER SCALE TROUGH ACROSS THE NW US AROUND TUESDAY. THIS WOULD BE
A COLDER SYSTEM WITH LOWER SNOW LEVELS TO START, BUT WOULD LIKELY
NOT HAVE AS MUCH DEEP MOISTURE AVAILABLE AS THE CURRENT SYSTEM
AND THERE IS STILL CONSIDERABLE UNCERTAINTY THIS THIS TIME WITH
MORE SPECIFIC DETAILS. HOENISCH
- FORECAST CONFIDENCE & SCENARIOS:
MAIN CONCERNS FOR WINTER WEATHER IMPACTS THROUGH THE REST OF THIS
AFTERNOON AND EVENING ARE IN AREAS THAT SEE THE HEAVIER SNOWFALL
RATES IN CONJUNCTION WITH WINDY CONDITIONS. THIS IS MOST LIKELY
ACROSS AREAS NEAR THE LITTLE BELTS/SNOWIES AND ADJACENT PORTIONS OF
JUDITH BASIN, FERGUS AND SOUTHEASTERN CASCADE COUNTIES. HOENISCH
AVIATION
23/18Z TAF PERIOD
WIDESPREAD RAIN/SNOW CONTINUES TO FALL THIS AFTERNOON AND INTO
THE EVENING ACROSS THE REGION. THE COLD FRONT WILL CONTINUE TO
USHER IN COLDER AIR, TRANSITIONING RAIN TO SNOW AT LOWER
ELEVATIONS THIS AFTERNOON. PRECIPITATION WILL CONTINUE TO BRING
MVFR TO LIFR CONDITIONS REGION WIDE. VLIFR CONDITIONS WILL BE
POSSIBLE AT TIMES AT KCTB AND KLWT DUE TO SNOW. RAIN/SNOW EXITS
BETWEEN 23/23Z TO 24/05Z. ALONG WITH PRECIPITATION, BREEZY TO
GUSTY NORTHWEST WINDS PERSISTS THROUGH THE AFTERNOON, DECREASING
IN THE EVENING. WIND GUSTS OF 50KTS WILL BE POSSIBLE AT KCTB.
-WILSON
PRELIMINARY POINT TEMPS/POPS
GTF 25 43 25 38 / 60 0 0 0
CTB 21 42 23 39 / 0 0 0 0
HLN 21 44 24 42 / 70 0 0 0
BZN 21 41 20 43 / 100 0 0 0
WYS 15 46 15 50 / 80 0 0 0
DLN 25 44 24 46 / 90 0 0 0
HVR 23 44 22 44 / 90 0 0 0
LWT 21 40 21 39 / 100 0 0 0
TFX WATCHES/WARNINGS/ADVISORIES
HIGH WIND WARNING UNTIL 6 PM MDT THIS EVENING FOR EASTERN TOOLE
AND LIBERTY-HILL COUNTY.
WINTER WEATHER ADVISORY UNTIL 3 AM MDT SATURDAY FOR BEARS PAW
MOUNTAINS AND SOUTHERN BLAINE-FERGUS COUNTY BELOW 4500FT-JUDITH
BASIN COUNTY AND JUDITH GAP-SNOWY AND JUDITH MOUNTAINS.
WINTER WEATHER ADVISORY UNTIL 9 PM MDT THIS EVENING FOR SOUTHERN
HIGH PLAINS-SOUTHERN ROCKY MOUNTAIN FRONT.
HIGH WIND WARNING UNTIL 9 PM MDT THIS EVENING FOR FERGUS COUNTY
BELOW 4500FT.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR BIG BELT,
BRIDGER AND CASTLE MOUNTAINS-ELKHORN AND BOULDER MOUNTAINS-
GALLATIN AND MADISON COUNTY MOUNTAINS AND CENTENNIAL MOUNTAINS-
LITTLE BELT AND HIGHWOOD MOUNTAINS-NORTHWEST BEAVERHEAD COUNTY-
RUBY MOUNTAINS AND SOUTHERN BEAVERHEAD MOUNTAINS-UPPER BLACKFOOT
AND MACDONALD PASS.
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